Skin preparations have been used for thousands of years to render a softer and more elastic sensation of the skin. These preparations are based on different components and work in different ways.
A frequently used component in skin preparations is lanolin, which is composed of hydrophobic esters, which oppose absorption of water. However, lanolin has been reported to cause allergic reactions in a high number of individuals.
Other frequently used components are water repellent films such as petrolatum, which however may cause maceration by preventing even normal moisture loss from the skin.
Furthermore, there are fats and oils of vegetable and animal origin, which are used in cosmetic formulations for their emollient, occlusive and moisturizing properties. Stability problems with these products require use of additives or stabilizers. These additives or stabilizers may however cause dermal problems.
Phospholipids have also been used as moisturizers in various creams and lotions. These lipids are complex fat substances found in living cells. Lecithin is an example of a typical phospholipid substance.
Still another type of skin preparations is disclosed in WO 9831399, which concerns preparations capable of forming an osmotic i.e. semi permeable membrane in the skin. These preparations are based on a combination of a lipophilic component, such as a fatty acid (stearic acid) or polysiloxane, and a hydrophilic component, such as triethanolamine.
Another type of skin preparations is based on vernix caseosa, which appears a cheesy deposit on the surface of human or animal foetuses and consists of about ⅓ of cholesterol esters. This type of preparations is described in e.g. U.S. Pat. No. 5,631,012 which concerns cosmetic compositions containing naturally occurring and/or synthesized vernix lipid mixtures in the same proportionate mixture. These compositions are described as moisturisers by functioning as a protective barrier between the skin and the environment.
Preparations based on vernix caseosa are also known from JP 10175843, which describes a skin composition containing vitamin E and cholesterol esters of mammal vernix origin. A disadvantage with cholesterol esters is that they do not penetrate the skin, but stays on its surface.
Another publication concerning compositions including vernix is disclosed in WO 99/44582. According to this publication a natural or synthetic vernix is dispersed in a film-forming amount in a biocompatible liquid such as dimethylsulfoxid, amniotic fluid and/or pulmonary surfactant to form a film. This publication also recognises the problem of achieving a controlled and uniform administration of the vernix substances through the skin.
From the above patent publications and other literature it is thus known that vernix could have a potential as a beneficial agent in skin preparations. A problem is however how to realize this effect and obtain a satisfactory effect.